Quality-Related Complex Nonlinear Process Monitoring

Nonlinear process is a common phenomenon in industrial processes, which shows a nonlinear relationship between the variables. Generally, PLS and its modifications (Yin et al. in IEEE Trans Industr Electron 62:1651–1658, 2015; Zhou et al. in AIChE J 56:168–178, 2010; Qin and Zheng in AIChE J 59:496–504, 2013) have a high performance when dealing with linear variation among process variables. However, when applied to a nonlinear process, which generally means that there exists a nonlinear relationship between X and Y, or the process data distributed nonlinearly, or both, these methods cannot perform well.